Molecular and morphological evidence reveals a hidden new taxon in the endemic genus Pseudocuneopsis (Bivalvia, Unionidae) from China.

A new species of freshwater mussel belonging to the genus , namely , is diagnosed and described from Guangxi Province, China. This paper provides a detailed shell morphological description, soft-body anatomical characteristics, and partial sequences of mitochondrial COI as DNA barcode data for the novel species. The new species can be distinguished from its congeners (, , and ) by shell shape, beak position, and surface sculpture. Phylogenetic analyses based on the mitochondrial COI gene reveal that forms a sister group with and exhibits an interspecific genetic distance of 5.1%. Therefore, we provide robust morphological and molecular evidence to support the validity of this new species.